1. Field of the Invention
This invention relates to a pattern forming apparatus and also to a pattern forming method. More particularly, the present invention relates to a pattern forming apparatus and a pattern forming method that can dramatically improve the throughput even when fine patterns with a size less than the wavelength of light and bold line patterns or solid large area patterns coexist.
2. Related Background Art
With the technological developments in the field of large capacity semiconductor memories and high speed CPUs using ICs in recent years, micronized optical lithography has become indispensable to the industry.
Micronized optical lithography has been realized by using short wavelength light for optical lithography systems. Currently, near ultraviolet laser beams are used for state-of-the-art micro-processing of about 0.1 xcexcm.
However, for further micronization, a number of technological problems have to be solved, including the use of laser beams with shorter wavelengths, development of lenses that can cope with such short wavelengths and so on.
Meanwhile, techniques using a near-field have been proposed for forming photoresist patterns with a width less than the wavelength of light by using light.
For instance, Japanese Patent Application No. 7-106229 discloses an exposure system using a near-field probe for scanning. The near-field probe is prepared by sharpening the front end of an optical fiber by wet etching.
However, since the known system disclosed in the above patent document uses a probe having a micro-aperture at the front end for pattern lithography, a long exposure time is required for preparing a large solid pattern. Therefore, such a system cannot dramatically improve the throughput.
In view of the above-identified circumstances, it is, therefore, an object of the present invention to provide a pattern forming apparatus and a pattern forming method that can produce patterns highly accurately to dramatically improve the throughput even when fine patterns and bold line patterns or solid large area patterns coexist.
In an aspect of the present invention, the above object is achieved by providing a pattern forming apparatus comprising:
a first exposure section capable of conducting pattern exposure for a predetermined line width;
a second exposure section for conducting pattern exposure for a line width greater than said predetermined line width of said first exposure section; and
means for detecting the relative positional relationship between said first exposure section and said second exposure section,
wherein pattern exposure is conducted by using said first exposure section and said second exposure section on the basis of the detected positional relationship.
In another aspect of the invention, there is provided a pattern forming method comprising the steps of:
detecting the positional relationship of a first exposure section capable of conducting pattern exposure for a predetermined line width and a second exposure section for conducting pattern exposure for a line width greater than said predetermined line width of said first exposure section; and
conducting a first exposure step using said first exposure section, subsequently aligning said second exposure section to an exposure position on the basis of the detected positional relationship and conducting a second exposure step using said second exposure section.